My driver side tail light and cab light and dash lights aren't working. I changed the headlight switch and when I turn it on it blows the fuse for the horn. Possible bad ground?

 

You have a short somewhere......

 

What color wires do I check under the hood?

 

Running lights and hazards work now, but no turn signals, backup lights.

 

Try this site for wiring diagrams. They *might* have 'em.

 

I changed the turn signal switch, now I have running lights and dash lights. Flashers work when the lights are off. Turn signal only works when I put a test light into the red and black wire in the turn signal plug. I'm thinking just loose or bad wiring into that plug?